The writing process for the majority of Metallicaâs albums have followed the same process. A large slew of guitar riffs written primarily by James Hetfield, sometimes Kirk Hammett, and rarely the bandâs bass player, (that now being bass virtuoso Robert Trujillo) are reviewed and selected.
1 Delhi is most polluted city in the world in PM2.5 concentrations. 2  Half of the top 20 most polluted cities were in India, according to data.  PM2.5 is considered most harmful to health.
April 29, 2009 -- Areas in California remain some of the most polluted in the U.S., with air quality that is likely damaging the health of millions of people, according to a report by the American Lung Association.he report finds that Los Angeles, Bakersfield, Calif., and Visalla-Porterville, Calif., rank among the five U.S. cities most polluted with particulate and ozone pollution.